A recent raft of research from the Bloomberg School of Public Health in the US has found that mild to moderate coffee intake was found to have positive effects against the development of type 2 diabetes.
Actual effective levels seem to be around 2-4 cups a day. Obviously the quality of the coffee is important and the study found significant positive data within the core group of over 12000 middle aged men and women who were enrolled in the Atherosclerosis Risk in Communities Study (ARICS) in the US.
While no link was found between those who drank sweetened beverages and type 2 diabetes, the researchers did find a link between coffee drinkers and the disease. This study adds weight to previous research which has highlighted the protective benefits of coffee against type 2 diabetes